1. Field of the Invention
This invention relates to joystick devices. More particularly, this invention is concerned with a joystick device having an operating axis (lever) arranged for tilt movement in a desired direction so as to output an electric signal depending upon a state of inclination in the lever (the direction and the angle of inclination).
2. Prior Art
One example of a joystick device is described for example in Japanese Provisional Utility Model Publication No. H2-68404. This conventional art joystick device has a pair of rocking members, each having an elongate hole arranged such that these elongate holes are placed perpendicular to each other. A lever is inserted through the respective elongate holes of the pair of the rocking members so that the lever is allowed to tilt in every direction about a predetermined point as a fulcrum point. The lever is projected to extend from a predetermined location of a cover attached to a case in which the rocking members are accommodated.
In the above conventional art, the lever has a lower portion inserted through an elongate hole of one rocking member to be attached to the same rocking member through a shaft extending perpendicular to a lengthwise direction of the elongate hole, thereby preventing the lever from being removed and from rotating about its own axis. Consequently, the fulcrum point of the lever is located on the shaft where the lower portion of the lever is attached to the rocking member. To this end, it is necessary to provide a relatively large opening in the cover in order to obtain a sufficient range of tilt movement of the lever.
However, if a large opening is formed in a cover, dust or dirt is often allowed to intrude into an interior of the case through the opening, impairing operational reliability in rotational or sliding portions of the joystick device.